Abstract: For patients with locally advanced primary or recurrent gynecologic cancers, prognosis is poor. Doses of external beam radiation therapy required to treat either gross or microscopic disease in patients previously irradiated or treated surgically exceed doses that are tolerated by normal anatomic structures. Intraoperative radiation therapy allows maximal tumor control achievable with radiation while minimizing radiation exposure of dose-limiting surrounding structures. Intraoperative radiation therapy is a unique treatment modality, allowing direct visualization of the target volume during a planned surgical procedure. Intraoperative radiation therapy has the potential to improve both long-term local control and overall survival especially in patients with para-aortic and/or pelvic sidewall recurrences.